1. Field of the Invention
The present invention relates to a monitor (surveillance) camera system (or apparatus) covering 360-degree monitoring area and a method of displaying an image from the same, and more particularly to a monitor camera system and a camera picture displaying method, which are capable of producing a display so that a portion of an image is masked for the purpose of the protection of privacy.
2. Description of the Related Art
So far, a monitor camera in which a camera and a rotatable table therefor are placed in a dome-like housing has been put on the market. This monitor camera is called a xe2x80x9ccompound cameraxe2x80x9d because of the camera being capable of, through movements of the rotatable tables, rotating horizontally (pan) while rotating vertically (tilt). The compound camera can rotate through 360 degrees without limitation in the pan directions, while rotating in an angular range between 0 degree and 90 degrees, that is, from a horizontal direction to a vertical direction, in the tilt directions. In addition, through the manipulation of a controller, this compound camera can take a photograph at a desired angle or in a desired direction in a state installed on a ceiling of public facilities or the like. Still additionally, even if a target subject passes right under it, as FIG. 15 shows, immediately a camera 10 turns to right under, it can rotate 180 degrees around a lens thereof to chase the target subject continuously, thus providing pictures throughout a monitoring area.
FIG. 13 is an illustration of a state in which a controller 12 for controlling a compound camera 11 and a monitor 13 for displaying a picture taken through the compound camera 11 are connected through a coaxial cable 16 to the compound camera 11. The controller 12 functions as a control element and comprises a joystick 14 and a numeric pad (numeric keys) 15.
This compound camera 11 is designed so that a plurality of camera positions, for example, taking a direction to an entrance, a direction to an exit and a direction to a window, are preset in the controller 12 in the form of identification numbers (ID). After preset, simply by inputting the ID corresponding to a camera position through the use of the numeric pad 15, the camera can be turned to take the preset direction.
In addition, the joystick 14 of the controller 12 is manipulated for controlling the moving (rotating) speed of the camera 11. When the joystick 14 is tilted, as shown in FIG. 14, the camera 11 rotates in a tilting direction at a speed proportional to the movement component of the joystick 14 in the vertical-axis direction and rotates in a panning direction at a speed proportional to the movement component thereof in the horizontal-axis direction. An operator checks pictures while viewing the monitor 13 and, when the rotating camera 11 catches a desired direction, the operator returns the joystick 14 to the neutral position to stop the rotations thereof in the tilting and panning directions.
Furthermore, when such a camera is installed to monitor a public place, the camera has a function whereby limitation is imposed on the angle of rotation of that camera so that neighboring private houses do not appear on the screen (scene) or has a picture processing function whereby, if the camera develops a picture of the private houses, the picture thereof entirely turns black, thereby accomplishing the protection of privacy.
However, with the conventional privacy protecting method for use in a monitor camera system, a picture other than an area undergoing the protection also disappears because limitation is imposed on photographing direction or the entire picture turns black, which causes impairment of the monitoring function.
Meanwhile, a group including the inventors of the present invention has developed a new compound camera capable of rotating 180 degrees in tilting directions while limitlessly rotating 360 degrees in panning directions. Although this compound camera can provide the increased degree of freedom in moving direction to functionally monitor a wider range, there is an additional need for a method to accomplish the privacy protection without reflecting on the monitoring function.
Accordingly, the present invention has been developed with a view to eliminating the above-mentioned problems, and it is an object of the invention to provide a monitor camera system and camera picture displaying method which are capable of protecting privacy from a camera picture without interfering with a monitoring function.
For this purpose, in accordance with an aspect of the present invention, a monitor camera system comprises a monitor camera ratatable in panning directions and in tilting directions and control means for controlling the monitor camera, the monitor camera holding mask data to be used in masking a privacy zone in a picture taken by the monitor camera, while the control means masking a portion of said picture corresponding to said privacy zone on the basis of the mask data.
In this case, the control means sets the mask data through the use of a contour parameter of a configuration of a mask zone for covering the privacy zone. More specifically, for setting the mask data, the control means uses, as the contour parameter, center coordinates and size coefficient of the mask zone configuration, center coordinates of said mask zone configuration and a radius of said mask zone configuration, or coordinates of a left upper vertex and a right lower vertex of the mask zone configuration. In addition, the setting of the mask data is made on a central portion of the picture taken by said monitor camera.
Alternatively, in the monitor camera system, the monitor camera holds the mask data produced on the basis of center coordinates and one or more contour size parameters of the mask zone configuration.
Furthermore, in the monitor camera system, the masking is inhibited in a region in which a tilt angle is below a predetermined value, and the control means manages the number of masks included in one scene taken by the monitor camera, and inhibits the setting of masks, whose number exceeds a predetermined value, in the one scene.
Still furthermore, in the monitor camera system, the mask data, together with a number or name indicative of a mask zone for covering the privacy zone, is held in the monitor camera, and when receiving the number or name from the control means, the monitor camera provides a display of a mask zone determined by the mask data held together with the number or name. That is, when receiving the number or name from the control means in a mask correction mode, the monitor camera provides a display of a mask zone corresponding to the number or name. Additionally, the monitor camera inverts vertically the mask data held therein when masking said privacy zone.
Moreover, the setting or cancellation of the mask data is made only when a password is inputted to said control means, and a position of a mask zone for covering the privacy zone deviates from a central position of a screen displaying a picture taken by the monitor camera, the monitor camera corrects the configuration of the mask zone. Additionally, when a plurality of mask zones appears in one scene, the monitor camera converts the plurality of mask zones into one enlarged mask zone prior to masking processing.
Still moreover, in a case in which a mask zone is set on a screen for displaying a picture taken by the monitor camera, the control means controls a moving speed of the monitor camera to a mask processing ability.
In addition, in accordance with another aspect of the present invention, there is provided a method of displaying a picture taken by a monitor camera ratatable in panning directions and in tilting directions, the method comprising a step of masking a portion of the picture corresponding to a privacy zone on the basis of mask data set through the use of a contour parameter of a configuration of a mask zone for covering the privacy zone.
In the picture display method, the masking is inhibited in a region in which a tilt angle is below a predetermined value, and when the mask zone deviates from a central portion of a screen for displaying the picture taken by the monitor camera, the mask zone configuration is corrected and displayed to cover the entire privacy zone. Additionally, the masking is stopped when a moving speed of the monitor camera exceeds a predetermined value.
Furthermore, in the picture display method, a number or name (character or symbol) is related to said mask data to be displayed together with said mask zone, and the mask zone is displayed in response to an input of the number or name for correction of the mask zone.